When running Mochitests we set the telemetry server to a bogus value [1], preventing Telemetry from uploading test pings. However, as shown in bug 1279821, this could clutter the logs and be confusing. We should consider disabling the ping upload in mochitests by making the "datareporting.healthreport.uploadEnabled" default to false there. [1] - http://searchfox.org/mozilla-central/rev/4039fb4c5833706f6880763de216974e00ba096c/testing/profiles/prefs_general.js#247